The present invention relates to an inductor-type generator, and more specifically to a fixed field inductor-type generator having a fixed field coil construction suited for being mounted on a vehicle and to a method of producing the same.
Conventional inductor-type generators designed for use being mounted on vehicles can be grouped into those of the so-called rotary field type in which an exciting current is supplied to a field coil via slip rings, and those of the so-called fixed field type without brushes. In the fixed field inductor-type generator without brushes with which the present invention is concerned, a field coil is suspended in a space formed between poles of the rotor as disclosed, for example, in Japanese Patent Publication No. 20642/1979. When the generator is to be mounted on an automobile, in particular, it is required that the generator withstand a temperature of as high as about 180.degree. C. from the engine and the vibration which is as intense as about 30 G. According to the above-mentioned conventional art, a holding member for holding the fixed field coil has a plurality of radially stretching legs which are inserted in coil-insertion grooves of the stator core, thereby to firmly hold the field coil. With the above-mentioned method, however, the armature coil is often damaged when the legs are inserted in the coil-insertion grooves, giving rise to the occurrence of dielectric breakdown, and the generator is assembled with poor efficiency.
According to the above-mentioned method, furthermore, the resin is poured into a relatively large clearance between the holding member and the field coil after the field coil has been incorporated in the coil-holding member that is secured in the stator core. Therefore, the strength for holding the field coil is reduced by the amount equal to the thickness of resin. When the generator is mounted on a motorcycle, in particular, the resin material is deteriorated, and the member holding the field coil loses strength quickly due to high temperatures and intense vibrations.